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lint-ran hra'rns PATENT rerun...

EMILE F. LOISEAU, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO J. PERCY KEA'IING, TRUSTEE.

ART OF MANUFACTURING PORTLAND CEMENT.

SPECIFICATION forming part of Letters Patent No.309,150, dated December-9,1884,

Application filed June 19, 1884. (No specimens.)

T on whom it may concern: I

Be it known that I, EMILE F. LOISEAU, of the city and county of Philadelphia, and State of Pennsylvania, have invented .a new and useful Improvement in the Art of Manufacturing Portland Cement, of which the following is a specification.

Portland cement manufactured by what is known among those skilled in the industry as IO the dry process is a product of the following composition: Limestone and clay, chalk or clay, or other similar materials are ground in the raw condition into powder. This powder is then wetted and made into bricks or I 5 cakes,which,after being dried on dryingfloors or steam-tables, are placed by hand within kilns,where they are burned to clinker. This clinker is subsequently ground, and is in its ground condition ready for the market.

I am aware that under Letters Patent No. 292,329, granted January 20, 1884, to Robert W. Lesley and James M. \Villcox, egg-shaped, hexagonahor rounded lumps or balls obtained by compressing moistened cement-powder l1 ave been substituted for the square-sided pieces formerly used, and with great advantage. In their process, however, where the material is 'too finely ground or too much moistened, it

often clogs and sticks to the rolls and molds used, thus causing delays and imperfect mold- My invention has for its object the obviating of this difficulty, and is an improvement upon the invention referred to.

Generally stated, my invention consists in the provision of means whereby the cementpowder maybe kept in a granulated condition before it goes upon the rolls or molds, thus insuring perfect molding. Such result I find 40 can be accomplished by the use of what may be termed binders, composed of coke-dust, coal, culm, raw cement-rock, raw limestone, or other similar material larger in size than the powder with which they are to be mixed. These binders,which are preferably of material having rough surfaces,are mixed with the cement-powder before the molding operation. The entire mass is then moistened in such de gree only as not to affect the granulated condition. The moistened granulated materialis then fed onto rolls or other molding machinery,the molded lumps then burned to a clinker in kilns, and then ground into cement. As will be readily perceived, the effect of the binders, by reason of theirlarger size, is to render the fine ground powder more granular, and to prevent it when moistened from getting into such pasty condition as would cause it to stick in the molds. They have, moreover. the further mechanical function of acting as binders, wedges, or ties, holding the material together when being molded and after it is molded.

IVhite coal, culm, coke dust, or sawdust may, byreason of their advantageous form, and also because they leave no injurious material behind after the burning to affect the quality of the cement, be used as binders. I do not confine myself to them alone, as cut wood shavings,cut straw,cut hay,and other kindred material may also be employed.

IVhen it is not desirable to use the above materials, the object of my invention may be attained by taking from the crushers where the raw cement materials are crushed a suitable portion of the crushed stone or chalk in 7 5 its rough condition before grinding, and adding it before moistening and molding to the cement-powder, the object in all cases being to incorporate with such powder rough material of larger size than the granules of powder, to act as binding-wedges.

Having thus described my invention and the best known means of carrying it into effect, what I claim, and desire to secure by Letters Patent, is-

The granulation of cementpowder before the molding operation by the addition thereto of binders or wedges of larger size than the grains composing the powder, and composed, preferably, of coke-dust, coal, culm, or raw cement or limestone,substantially as set forth.

In testimony whereof I have hereunto signed my name this 17th day of June, A. D. 1884.

EMILE F. v LOISEAU.

In presence of J. BONSALL TAYLOR,

W. G. Srnliwnnrnen. 

